In this work an
improved self-calibrating radial GRAPPA algorithm for real-time cardiac MRI
is presented. It is shown that by subtracting the temporal average prior to
the parallel MRI reconstruction significantly improved image quality can be
achieved over pure radial GRAPPA. Real-time cardiac imaging data at a frame
rate of 20fps in 2mm in-plane resolution are shown using only 16 radial
projections per frame.